Introduction Of Carbon Dots Research Articles

Carbon Dots Anchoring Single-Atom Pt on C3N4 Boosting Photocatalytic Hydrogen Evolution.

Carbon nitride (C3N4) has gained considerable attention and has been regarded as an ideal candidate for photocatalytic hydrogen evolution. However, its photocatalytic efficiency is still unsatisfactory due to the rapid recombination rate of photo-generated carriers and restricted surface area with few active sites. Herein, we successfully synthesized a single-atom Pt cocatalyst-loaded photocatalyst by utilizing the anchoring effect of carbon dots (CDs) on C3N4. The introduction of CDs onto the porous C3N4 matrix can greatly enhance the specific surface area of C3N4 to provide more surface-active sites, increase light absorption capabilities, as well as improve the charge separation efficiency. Notably, the functional groups of CDs can efficiently anchor the single-atom Pt, thus improving the atomic utilization efficiency of Pt cocatalysts. A strong interaction is formed via the connection of Pt-N bonds, which enhances the efficiency of photogenerated electron separation. This unique structure remarkably improves its H2 evolution performance under visible light irradiation with a rate of 15.09 mmol h-1 g-1. This work provides a new approach to constructing efficient photocatalysts by using CDs for sustainable hydrogen generation, offering a practical approach to utilizing solar energy for clean fuel production.

Efficient Protection of Paper‐Based Cultural Relics via In Situ Synthesis of Carbon Dots/Layered Double Hydroxide

AbstractPaper‐based cultural relics are of great value and have been facing irreversible damage caused by multiple factors, among which acid hydrolysis and ultraviolet photodegradation are the main processes leading to paper deterioration. Paper protection highly relies on a limited range of materials with single functions, and the design of new materials that ensure long‐term safety and efficiency by simultaneously addressing the issues of acidification and UV degradation in paper is highly desired. In this study, the introduction of carbon dots (CDs)‐enhanced layered double hydroxides (LDH) 0D/2D nanohybrids (CDs/Mg‐Al LDH)  is proposed as novel dual‐functional materials for paper protection against UV degradation and acidification. Through a CDs‐assisted in situ growth strategy, CDs/Mg‐Al LDH with ultrathin thickness (≈9.1 nm) and CDs‐intercalated structure are achieved. The CDs/Mg‐Al LDH nanohybrids demonstrate high dispersibility, strong UV absorption, and remarkable photostability, resulting in protected‐paper with decelerated acidification, oxidation, and yellowing degradation processes under both accelerated UV‐aging and dry‐heat conditions. Additionally, the protected‐paper can emit uniform blue light under 365 nm UV excitation allows for easy identification of the distributed CDs/Mg‐Al LDH within the paper, marking a unique and practical feature. This research paces a new direction for the protection of paper‐based relics with emerging carbon dots‐based 0D/2D nanomaterials.

Exploring the potential applications of amphiphilic carbon dots based nanocomposite hydrogel in liquid chromatographic separations

BackgroundDue to their excellent stability, low toxicity, flexible modification and adjustable functionality, carbon dots (CDs) have a promising application prospect in the field of chromatographic stationary phases. Hydrogels are new functional polymer materials with three-dimensional network structure that have excellent hydrophilicity, high porosity and unique mechanical properties, which are also good candidate materials for liquid chromatography. Nevertheless, a review of the literature reveals that CDs based nanocomposite hydrogels have not yet been reported as HPLC stationary phases. ResultsIn this work, amphiphilic CDs with multiple functional groups and polyacrylic acid hydrogel were grafted to the surface of silica gel by an in-situ polymerization method, and a CDs/polyacrylic acid nanocomposite hydrogel stationary phase (CDs/hydrogel@SiO2) was prepared. CDs act as the macroscopic cross-linking agents to form a cross-linked network with polyacrylic acid chains through physical cross-linking by hydrogen bonding and chemical cross-linking by amidation and esterification reactions, which not only improve the swelling property of the hydrogel but also increase its stability. Additionally, the introduction of CDs with multifunctional groups modulates the hydrophilic-hydrophobic balance of the hydrogel that also imparts good hydrophobicity to the composite hydrogel. Through the study of retention mechanism and influencing factors, it is certificate that the CDs/hydrogel@SiO2 has mixed-mode chromatographic performance. Furthermore, the CDs/hydrogel@SiO2 column shows great potential for the determination of organic contaminants in environmental water samples. SignificanceThis work confirms the potential application of CDs/hydrogel composite for the separation of various samples and provides the possibility of developing CDs based nanocomposite hydrogel in the field of liquid chromatography. Introducing CDs into hydrogel can open up a new way for nanocomposite hydrogels to be used in HPLC, which expands the advance of hydrogel and CDs in separation field.

Low platinum loading electrocatalyst supported on a carrier derived from carbon dots doped ZIF-67 for the ORR and zinc-air batteries.

The development of economical and efficient platinum-based catalysts for the oxygen reduction reaction (ORR) is considered the most promising strategy for the widespread application of clean energy conversion devices. Herein, Co nanoparticles encapsulated in N-doped carbon carriers, CoCN(CDs-X), were constructed by pyrolyzing carbon dots (CDs) doped ZIF-67 and further used to anchor Pt to prepare low Pt loading catalysts, PtCoCN(CDs-X). The introduction of CDs not only improves the conductivity for efficient electron transfer, but also regulates the interaction between Pt and the CoCN(CDs-X) support and alleviates the oxidation of Pt. The optimized PtCoCN(CDs-0.10) displays decent ORR behavior with onset and half-wave potentials of 0.95 V and 0.83 V, respectively, in alkaline media and superior catalytic stability and methanol tolerance. While employing PtCoCN(CDs-0.10) as a cathode catalyst for an as-assembled zinc-air battery (ZAB), it delivers an excellent power density of 194.2 mW cm-2 and exceptional operation stability, which is indicated by a voltage efficiency loss of only 7.7% after a long cycle life of 100 h, demonstrating its great potential applications.

A Sonoresponsive and NIR-II-Photoresponsive Nanozyme for Heterojunction-Enhanced "Three-in-One" Multimodal Oncotherapy.

Although low-cost nanozymes with excellent stability have demonstrated the potential to be highly beneficial for nanocatalytic therapy (NCT), their unsatisfactory catalytic activity accompanied by intricate tumor microenvironment (TME) significantly hinders the therapeutic effect of NCT. Herein, for the first time, a heterojunction (HJ)-fabricated sonoresponsive and NIR-II-photoresponsive nanozyme is reported by assembling carbon dots (CDs) onto TiCN nanosheets. The narrow bandgap and mixed valences of Ti3+ and Ti4+ endow TiCN with the capability to generate reactive oxygen species (ROS) when exposed to ultrasound (US), as well as the dual enzyme-like activities of peroxidase and glutathione peroxidase. Moreover, the catalytic activities and sonodynamic properties of the TiCN nanosheets are boosted by the formation of HJs owing to the increased speed of carrier transfer and the enhanced electron-hole separation. More importantly, the introduction of CDs with excellent NIR-II photothermal properties could achieve mild hyperthermia (43°C) and thereby further improve the NCT and sonodynamic therapy (SDT) performances of CD/TiCN. The synergetic therapeutic efficacy of CD/TiCN through mild hyperthermia-amplified NCT and SDT could realize "three-in-one" multimodal oncotherapy to completely eliminate tumors without recurrence. This study opens a new avenue for exploring sonoresponsive and NIR-II-photoresponsive nanozymes for efficient tumor therapy based on semiconductor HJs.

Carbon Dots as an Electron Acceptor in the ZnIn2S4@MIL-88A Heterojunction for Enhanced Visible-Light-Driven Photocatalytic Hydrogen Evolution.

In this study, visible-light-responsive carbon dots (CDs)/ZnIn2S4@MIL-88A (C/ZI@ML) photocatalysts were successfully prepared through in situ loading CDs and ZnIn2S4 nanosheets on MIL-88A(Fe) to form a ternary heterojunction. The detailed characterization indicated that the two-dimensional ZnIn2S4 nanosheets were uniformly coated on the surface of MIL-88A(Fe), and ZnIn2S4/MIL-88A(Fe) exhibited enhanced photocatalytic hydrogen production performance (1259.63 μmol h-1 g-1) compared to that of pristine MIL-88A(Fe) and ZnIn2S4 under visible light illumination. After introduction of CDs into ZnIn2S4/MIL-88A(Fe), the C/ZI@ML catalyst remarkably enhanced the photocatalytic activity and the hydrogen evolution rate of 1C/ZI@ML was up to 3609.23 μmol g-1 h-1. The photoinduced charge carriers of C/ZI@ML can be efficiently separated and migrated because of the close contacted interface, synergistic effect, and suitable band structure. In combination with photoelectrochemical experiments and electron paramagnetic resonance spectra, a possible photocatalytic mechanism over C/ZI@ML was proposed. This work demonstrated a facile preparation method for fabricating efficient visible-light-driven heterojunction photocatalysts.

Visible light assisted heterojunction composite of AgI and CDs doped ZIF-8 metal-organic framework for photocatalytic degradation of organic dye

• CDs@ZIF-8@AgI was prepared by a solvent-free way coupled to ion deposition strategy. • Acridine Orange can be effectively degraded by CDs@ZIF-8@AgI under visible light. Water pollution induced by the productive process of organic dyes would lead to various diseases, and so treatment of the wastewater is an urgent task for protecting human health and ecological environment. In this work, visible light responsive heterojunction material based on silver iodide and carbon dots (CDs) doped ZIF-8 metal organic frameworks (CDs@ZIF-8@AgI) has been prepared by a green solvent-free strategy and in-situ ion deposition method. The CDs@ZIF-8@AgI composites have high photocatalytic performance for degradation of acridine orange (AO) dye under visible light, and the maximum degradation percentage can reach to 96.0%, which was estimated by the UV-visible spectroscopy. The porous structure and large surface area of the photocatalyst were favorable to absorption of the target dye on the catalyst, which can promote the kinetic degradation rate for low level concentration of the dye. The introduction of CDs into the AgI heterojunction can improve the electron transport efficiency and visible light absorption capacity, and thus significantly enhancing the photocatalytic activity of the catalyst. The photocatalytic mechanism was proposed as indirect Z-scheme heterojunction type based on the energy band structure of the catalyst. This work provides a visible light photocatalyst for removal of the AO dye in wastewater and offers a promising strategy for developing photocatalyst for treatment of organic pollutants in the environment using solar energy.

Carbon dots decorated on the ultrafine metal sulfide nanoparticles implanted hollow layered double hydroxides nanocages as new-type anodes for potassium-ion batteries

Carbon dots decorated on the ultrafine metal sulfide nanoparticles implanted hollow layered double hydroxides nanocages (CDs@LDH-S) were employed as anode for potassium-ion battery. CDs@LDH-S exhibits an excellent long-term lifespan achieving 188 mAh g −1 after 8000 cycles at 1.0 A g −1 . • Carbon dots-LDH hybrid were used as anodes for potassium-ion batteries. • It delivers long-term lifespan with 188 mAh g −1 after 8000 cycles at 1.0 A g −1 . • DFT calculations and ex-situ characterizations were given to reveal mechanism. Although layered double hydroxides (LDH) stands out among various electrode materials with considerable theoretical capacities, the intrinsically poor electronic conductivity and inevitable aggregations of the fragile 2D structure impede their practical application in rechargeable metal-ion battery. In the present work, nickel/cobalt LDH hollow nanocages derived from metal-organic frameworks (MOFs) were synthesized. Afterward, the ultrafine metal sulfide nanoparticles were implanted into the LDH nanocages (LDH-S) through a in-situ sulfide method. Such a LDH-S architecture achieves an initial discharge capacity of 1387 mAh g −1 and stable specific capacity of 391 mAh g −1 at 0.1 A g −1 after 200 cycles while using as potassium-ion battery anode material. In addition, when LDH-S nanocages are decorated with carbon dots (CDs@LDH-S), it exhibits an excellent long-term lifespan achieving 188 mAh g −1 after 8000 cycles at 1.0 A g −1 . With the aid of ex-situ characterization and density functional theory (DFT) calculation, the excellent performance of CDs@LDH-S can be contributed to the hetero-structure, in which the interlayer confinement of ultrafine metal sulfides enhances the electrical/ionic conductivity. Furthermore, the well-defined internal voids and functional shells promise intimate contact between the electrolyte and electrode material, and also could avoid agglomeration during repeated potassium-ion insertion and extraction process. In addition, the presence of carbon dots (CDs) further enhances the electrical conductivity and stabilizes the electrode structure. This work proves that LDH-based anode with high capacity and low cost may be one of the promising candidates for potassium-ion storage and the introduction of CDs maybe an efficient way for construction of high-efficient electrode materials for potassium-ion storage.

Enhanced electrocatalytic performance of 2D Ni-MOF for ethanol oxidation reaction by loading carbon dots

Due to the scarcity of precious metals, it is urgently desired to develop novel non-precious metal catalysts for ethanol oxidation reactions (EOR) to improve the property of direct ethanol fuel cells (DEFCs), but it is still a huge challenge. Currently, nickel-based catalysts are known as one of the candidates to replace precious metal catalysts. Among them, nickel-based metal-organic frameworks (MOFs) have been treated as a new platform towards the development of electrocatalysts. Herein, a 2D Ni-MOF 1 was solvothermally synthesised, and combines with carbon dots (CDs) for enhancing the conductivity of MOF 1 to prepare finally MOF1-CDs@CC composites. The current density (j) of the optimal MOF1-CDs@CC toward EOR is 119 ​mA ​cm−2, which exceed those of the EOR catalysts previously reported. Meanwhile, the optimal MOF1-CDs@CC has low Tafel slope (93.9 ​mV dec−1) and high exchange j value (2.06 ​× ​10−5 ​A ​cm−2). The excellent performance of MOF1-CDs@CC is mainly ascribed to accelerating EtOH adsorption on the surface of the catalyst and charge transfer after the introduction of CDs. After 10000 ​s durability test, the retention rate of the j value of MOF1-CDs@CC is 90% of that (118 ​mA ​cm−2) of the original one, which indicates that MOF1-CDs@CC catalyst has good stability. So MOF1-CDs@CC is expected to be used as a cost-effective EOR electrocatalyst due to its simple preparation method, excellent activity and stability.

Carbon dots induced in-situ formation of porous europium micro-networks with enhanced photocatalysis

Excellent photocatalysts are highly desirable for clean energy and pollutant treatment. Carbon dots (CDs)-based composite photocatalysts have been widely studied and utilized in catalytic fields. However, the preparation of the photocatalysts with high catalytic activity still faces a great challenge. Herein, white-light-driven CDs-based porous europium micro-networks (CDs@P-Eu-MNs) composite photocatalysts are prepared by a facile in-situ growth strategy. CDs can affect the morphology and produce a large number of porous structures of CDs@P-Eu-MNs. Importantly, the introduction of CDs not only increases the light absorption, but also promotes the separation of photogenerated charge carriers, and thus improve photocatalytic performance of CDs@P-Eu-MNs composites. CDs@P-Eu-MNs show the highest photocurrent density, which can be used for the highly-efficient photodegradation of rhodamine 6G dyes with almost 95% degradation rate under low power white light (20 W) without any radical generating agents such as H2O2. Therefore, this new and efficient CDs@P-Eu-MNs photocatalyst will have a great application prospect in water pollution treatment.

PtNi Nanoparticles Loading on Sandwich-Like Hybrid Nanocarbon Support for Methanol Oxidation

A novel electrocatalyst, PtNi-graphene/carbon dots/graphene (PtNi/GCG), for methanol oxidation was prepared onto the glassy carbon electrode (GCE). The GCG hybrid nanocarbon support with sandwich-structure was dried onto GCE surface. Then, PtNi bimetallic nanoparticles were modified loaded on the GCG hybrid nanocarbon support via electrodeposition to obtain PtNi/GCG electrocatalyst. The as-prepared PtNi/GCG electrocatalyst was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and electrochemical analysis. The structure of PtNi/GCG shows that the PtNi nanoparticles were dispersed between the layered graphene. From electrochemical analysis, compared with Pt and PtNi/graphene catalysts, the as-prepared PtNi/GCG in this work has much better electrocatalytic properities towards methanol oxidation and shows better stability. The sandwich-structured electrocatalyst showed improved performance towards the methanol oxidation. The reason can be attributed to the synergistic effect between metals and the introduction of carbon dots between graphene layers. What’s more, carbon dots loading onto graphene layers effectively, which not only can increase the electrical conductivity, make available more active sites and reactive surface area, but also can enhance the dispersion of PtNi nanoparticles in the composite catalyst.

Carbon dots as an additive for improving performance in water-based lubricants for amorphous carbon (a-C) coatings

As a new type of carbon material, carbon dots (CDs) with exceptional properties are regarded as a type of potential water-based lubricant additive. In this study, it is first demonstrated that CDs perform excellently when used as lubricant additives for water-lubricated amorphous carbon (a-C) contacts. The results show that the introduction of CDs into water at a concentration of 0.1 wt% could reduce friction and wear in a-C contacts by 33% and 80%, respectively. Additionally, the lubricating performance of CDs is highly sensitive to its adding concentration. The excellent tribological performance of CDs results from the minimized CDs sediment particles (deposited in situ on worn a-C surfaces) and the reduced friction and wear via nano-bearing and nano-filling mechanisms. With high CDs concentrations, however, micron and submicron-sized sediment particles form when friction occurs and cause undesirable abrasive wear. For water-lubricated a-C contacts, therefore, the CDs concentration is the crucial determinant of lubrication performance that has to be appropriately controlled.

Role of carbon nanodots in defect passivation and photo-sensitization of mesoscopic-TiO2 for perovskite solar cells

In this work, a recently developed carbon nanodots (CnDs) were introduced in the mesoscopic TiO2 to form a TiO2: CnDs composite, to be used as an electrode in CH3NH3PbI3 based perovskite devices. It resulted the improvement in morphology of perovskite film and induced a carbon-doping passivating the oxygen defects. In addition, the presence of carbon dots enhanced the charge carrier mobility of TiO2 and provided extra photo-generation ability to the perovskite device due to its absorbing nature. The improved morphology, carbon-doping, photogeneration ability and the improved charge transfer characteristics with the introduction of carbon dots was verified by the scanning electron microscopy (SEM), atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV-visible absorption, X-ray diffraction, space charge limited current (SCLC) measurement, photoluminescence (PL), electrochemical impedance spectroscopy (EIS), current leakage and open circuit photovoltage decay (OCPD) measurements. An optimized concentration of CnDs (3 wt%) within the TiO2 resulted in a maximum power conversion efficiency of 19.45% with negligible hysteresis, which is 16% higher than the device with pristine TiO2.

Green synthesis of nitrogen and sulphur doped carbon dot composites for the sensing of glucose

The incredible properties of carbon dots (CDs) make them applicable to live cell imaging in biology, materials, catalysis, optics and sensors . The composites of doped carbon dots have received much more attention because very little concentration of carbon dots can be effectively dispersed or embedded in a biocompatible polymeric matrices to achieve the advanced properties of composites of cdots in comparison with the bare cdots. Thus an elegant green synthetic strategy towards the single pot synthesis of nitrogen and sulphur doped carbon dots were performed in an efficient manner in the present investigation. The formation of N and S doped cdots were confirmed from the UV- Visible spectral studies and fluorescene measurements. The morphology and size of the C dots were established by High resolution TEM. It is interestingly noticed that the introduction of carbon dots in the water soluble polymeric networks like polyvinyl acohol (PVA) i,e, the composites of carbon dots enhances the stability and the photo luminescent properties. The composites of cdots were found to sense the glucose from aqueous solutions even in the femto molar concentration range

Preparation and Characterization of Bacterial Cellulose-Carbon Dot Hybrid Nanopaper for Potential Sensing Applications

Green and facile approaches aiming at the manufacture of biocompatible paper-based optical sensors reporting the presence of photoluminescence (PL) modulating compounds is an emerging field of research. This study investigates the preparation of bacterial cellulose nanopaper containing covalently immobilized carbon dots for potential biosensing applications. Preliminary work of this feasibility study included TEMPO-mediated ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl-mediated) oxidation and nanofibrillation of bacterial cellulose (TOBC) on the one hand as well as synthesis and comparative analysis of different types of carbon dots (CDs) on the other hand. The two source materials of the targeted functional nanopaper were finally linked to each other by two different N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/ N-hydroxysuccinimide (EDC/NHS) coupling approaches to clarify whether grafting of CDs prior to or after TOBC paper formation would be the method of choice. Synthesis of the carbon nanodots was accomplished by microwave-assisted co-hydrothermolysis of appropriate precursor compounds. After isolation and purification by dialysis particles in the single-digit nanometer-range were obtained and characterized with regard to their photoluminescence properties in terms of emission wavelength, pH stability, and quantum yield. All types of synthesized CDs reached their PL maxima (450–480 nm; light blue) in a narrow excitation wavelength range of 340–360 nm. Variation of molar (C/N) ratio of the CD precursors and substitution of the nitrogen donor EDEA by urea increased PL and quantum yield (QY), respectively. The highest relative QY of nearly 32% was obtained for CDs synthesized from citric acid and urea. PL of all CDs was virtually insensitive to pH changes in the range of 4–10. Tensile testing of hybrid nanopaper prepared after EDC/NHS-mediated grafting of GEA-type CDs onto TOBC (0.52 mmol·g−1 COOH) in dispersion state revealed that both stiffness and strength are not compromised by incorporation of carbon dots, while plastic deformation and elongation at break increased slightly compared to nanopaper formed prior to decoration with CDs. Water contact angle of the nanopaper is unaffected by introduction of carbon dots which is supposedly due to the presence of surface amino- and amide groups compensating for the loss of carboxyl groups by grafting.

Efficient carbon dots/NiFe-layered double hydroxide/BiVO4 photoanodes for photoelectrochemical water splitting

Modification of semiconductor photoanodes with oxygen evolution catalyst (OEC) is an effective approach for improving photoelectrochemical (PEC) water splitting efficiency. In the configuration, how to increase the activity of OEC is crucial to further improve PEC performance. Herein, a ternary photoanode system was designed to enhance PEC efficiency of photoelectrodes through introducing carbon dots (CDs), NiFe-layered double hydroxide (NiFe-LDH) nanosheets on BiVO4 particles. Systematic research shows that NiFe-LDH serves as an OEC which accelerates oxygen evolution kinetics, while the introduction of CDs can further reduce charge transfer resistance and overpotential for oxygen evolution. Under the synergistic effect of NiFe-LDH and CDs, the photocurrent and incident photon to current conversion efficiency (IPCE) of the resulting CDs/NiFe-LDH/BiVO4 photoanode is improved significantly than those of the NiFe-LDH/BiVO4 electrode. Consequently, such a ternary heterostructure could be an alternative way to further enhance PEC water splitting performance.

Carbon Dots as Fillers Inducing Healing/Self-Healing and Anticorrosion Properties in Polymers.

Self-healing is the way by which nature repairs damage and prolongs the life of bio entities. A variety of practical applications require self-healing materials in general and self-healing polymers in particular. Different (complex) methods provide the rebonding of broken bonds, suppressing crack, or local damage propagation. Here, a simple, versatile, and cost-effective methodology is reported for initiating healing in bulk polymers and self-healing and anticorrosion properties in polymer coatings: introduction of carbon dots (CDs), 5 nm sized carbon nanocrystallites, into the polymer matrix forming a composite. The CDs are blended into polymethacrylate, polyurethane, and other common polymers. The healing/self-healing process is initiated by interfacial bonding (covalent, hydrogen, and van der Waals bonding) between the CDs and the polymer matrix and can be optimized by modifying the functional groups which terminate the CDs. The healing properties of the bulk polymer-CD composites are evaluated by comparing the tensile strength of pristine (bulk and coatings) composites to those of fractured composites that are healed and by following the self-healing of scratches intentionally introduced to polymer-CD composite coatings. The composite coatings not only possess self-healing properties but also have superior anticorrosion properties compared to those of the pure polymer coatings.

G-C3N4/AgBr nanocomposite decorated with carbon dots as a highly efficient visible-light-driven photocatalyst

Visible-light-driven photocatalysis as a green technology has attracted intense interest due to its potential applications in environmental remediation. However, the poor visible light utilization and low electron-hole separation efficiency of photocatalysts largely limited their practical application. In this work, a new ternary visible-light driven photocatalyst of g-C3N4/CDs/AgBr has been prepared by the introduction of carbon dots (CDs) onto the surface of g-C3N4, followed by in-situ growth of AgBr nanoparticles on CDs-modified g-C3N4 nanosheets. The g-C3N4/CDs/AgBr nanocomposite exhibits excellent photocatalytic efficiency for organic pollutant degradation, which is about 4.0, 5.3 and 2.3 times higher than that of AgBr, g-C3N4 and g-C3N4/AgBr, respectively. The result indicates the introduction of CDs into g-C3N4/AgBr can largely improve the photocatalytic activity since CDs act as the light absorber and the electron mediator between g-C3N4 and AgBr, which effectively promote the separation of photogenerated charge carriers and the utilization of visible light. Moreover, the photocatalytic activity of g-C3N4/CDs/AgBr has no obvious decrease after four photodegradation cycles, demonstrating a high photocatalytic stability. This study highlights the potential application of highly efficient CDs decorated photocatalysts in waste water purification.

Stabilizing alkenyl succinic anhydride (ASA) emulsions with starch nanocrystals and fluorescent carbon dots

Stabilizing alkenyl succinic anhydride (ASA) emulsions using fine particles instead of cationic starch have attracted much attention in recent years. Herein, starch nanocrystals (SNCs) made from maize starch by H2SO4 hydrolysis were used to co-stabilize ASA emulsions with fluorescent carbon dots (CDs) made hydrothermally from gelatin. The introduction of CDs can significantly enhance the stability and reduce the droplet size of SNC-stabilized ASA-in-water emulsions. Consequently, the sizing performance of the SNC-stabilized ASA emulsion is significantly improved by increasing the CD-to-SNC mass ratio. SNC and CD co-stabilized ASA emulsions show much better sizing performance than starch and CD co-stabilized ASA emulsions, achieving their best sizing performance at a CD-to-SNC mass ratio of 80%. Meanwhile, the morphology of SNC/starch and CD co-stabilized ASA emulsions can be traced under UV excitation.

Multifunctional nanotube-like Fe3O4/PANI/CDs/Ag hybrids: An efficient SERS substrate and nanocatalyst

In this paper, the stable and environment-friendly Fe3O4 nanotubes with polyaniline (Fe3O4 NTs/PANI hybrids) have been prepared via mesoporous anodic alumina oxide (AAO) template, sol–gel method and in-situ polymerization. Then multifunctional Fe3O4 NTs/PANI/Ag hybrids have been obtained by decorating Ag nanoparticles by glucose reduction on surface of Fe3O4 NTs/PANI hybrids. The morphologies and structures of these hybrids were subsequently investigated by SEM, XRD, TEM and XPS measurements. The Fe3O4 NTs/PANI/Ag hybrids presented high catalytic activity due to the template-assisted presence, preventing Ag particulate agglomeration. Importantly, the Fe3O4 NTs/PANI/Ag hybrids achieve sensitive surface-enhanced Raman scattering (SERS) signals. Furthermore, the introduction of carbon dots (CDs) endows these hybrids good dispersion and stable photoluminescence (PL). Therefore, the obtained hybrids may have potential applications in waste water treatment, biomedicine, photocatalyst, and environmental analysis.